My first full computer. Been working on it for a couple of months.

The specs:

• Variable size: 10 bits 
• ROM size: 512 bytes
• 16 commands, including a random number generator
• 8 registers

Commands (R is a register, C is a constant value):

MOV R, R/C: Moves B into A
ADD R, R/C: Adds B to A, stores in A
INC R: Increments A, stores in A, wraps 1023 around to 0
DEC R: Decrements A, stores in A, wraps 0 around to 1023
AND R, R/C: Performs AND on A and B, stores in A
OR R, R/C: Performs OR on A and B, stores in A
XOR R, R/C: Performs XOR on A and B, stores in A
LSH R, R/C: Shifts A left LSSB of B bits, stores in A
RSH R, R/C: Shifts A right LSSB of B bits, stores in A
JMP R/C: Jumps to index A of ROM
JEZ R/C, R: Jumps to index A of ROM if B is equal to zero, else continues
JOV R/C: Jumps to index A of ROM if the last ADD operation resulted in an overflow, else continues
IN R: Halts until an input signal is given, then moves the input bus to A
OUT R/C: Moves A to the output bus and gives a signal
RND R: Moves a random number from 0 to 1023 into A
HLT: Halts program

INC and DEC is much faster than adding and subtracting due to the adder design.

FILT ctype layout:

DCBA9876543210FEDCBA9876543210
MUUUCCCCr1111111111r2222222222
M: Must be set
U: Unused
C: Command
r: Sets whether arg 1 is a register value or a constant (1 for register, 0 for constant)
1: Arg 1
r: Sets whether arg 2 is a register value or a constant (1 for register, 0 for constant)
2: Arg 2

Compiler and ROM loader scripts

^Definitely a work in progress!

The biggest bottlenecks in this computer are the circuits that load arguments A and B (which may include fetching from registers). I'd love to be able to do this in parallel instead of one after the other in my next computer.